[sb2] Add mapping for aligned workspace mount points. JB#49476

Applies when sb2 is used under the SDK build engine.

Workspace directories used to be mounted at fixed paths under /home.
Now the mount point paths are chosen in a way that they align with the
source paths on host (e.g. "/home/user/work" -> "/home/user/work",
"C:\Users\user\work" -> "/c/Users/user/work").

scratchbox2/modes/obs-rpm-build+pp/config.lua

@@ -23,6 +23,9 @@ exec_policy_selection = {
                 -- the home directory is expected to contain target binaries:
                 {dir = sbox_user_home_dir, exec_policy_name = "Target"},
 
+                -- the workspace directory is expected to contain target binaries:
+                {dir = sbox_user_workspace, exec_policy_name = "Target"},
+
 		{prefix = tools, exec_policy_name = "Tools"},
 
 		-- DEFAULT RULE (must exist):

scratchbox2/modes/obs-rpm-build+pp/fs_rules.lua

@@ -803,6 +803,12 @@ import_from_fs_rule_library("user_rules")
 -- path convention
 use_outside_path("/parentroot")
 
+-- Define sbox_user_workspace as being outside like /home, this is a Mer SDK
+-- path convention. Take care to not override /home rules accidentally as those may overlap
+if sbox_user_workspace ~= "/home" then
+	use_outside_path(sbox_user_workspace)
+end
+
 -- Now run ~/.sbrules
 run_user_sbrules()
 

scratchbox2/modes/obs-rpm-build/config.lua

@@ -22,6 +22,9 @@ exec_policy_selection = {
                 -- the home directory is expected to contain target binaries:
                 {dir = sbox_user_home_dir, exec_policy_name = "Target"},
 
+                -- the workspace directory is expected to contain target binaries:
+                {dir = sbox_user_workspace, exec_policy_name = "Target"},
+
 		-- DEFAULT RULE (must exist):
 		{prefix = "/", exec_policy_name = "Host"}
 }

scratchbox2/modes/obs-rpm-build/fs_rules.lua

@@ -659,6 +659,12 @@ import_from_fs_rule_library("user_rules")
 -- path convention
 use_outside_path("/parentroot")
 
+-- Define sbox_user_workspace as being outside like /home, this is a Mer SDK
+-- path convention. Take care to not override /home rules accidentally as those may overlap
+if sbox_user_workspace ~= "/home" then
+	use_outside_path(sbox_user_workspace)
+end
+
 -- Now run ~/.sbrules
 run_user_sbrules()
 

scratchbox2/modes/obs-rpm-install/config.lua

@@ -22,6 +22,9 @@ exec_policy_selection = {
                 -- the home directory is expected to contain target binaries:
                 {dir = sbox_user_home_dir, exec_policy_name = "Target"},
 
+                -- the workspace directory is expected to contain target binaries:
+                {dir = sbox_user_workspace, exec_policy_name = "Target"},
+
 		-- DEFAULT RULE (must exist):
 		{prefix = "/", exec_policy_name = "Host"}
 }

scratchbox2/modes/obs-rpm-install/fs_rules.lua

@@ -487,6 +487,12 @@ import_from_fs_rule_library("user_rules")
 -- path convention
 use_outside_path("/parentroot")
 
+-- Define sbox_user_workspace as being outside like /home, this is a Mer SDK
+-- path convention. Take care to not override /home rules accidentally as those may overlap
+if sbox_user_workspace ~= "/home" then
+	use_outside_path(sbox_user_workspace)
+end
+
 -- Now run ~/.sbrules
 run_user_sbrules()
 

scratchbox2/rule_lib/fs_rules/user_rules.lua

@@ -3,6 +3,14 @@
 fs_rule_lib_interface_version = "105"
 ----------------------------------
 
+-- Workspace root from sbox' point of view is not the mount point but already
+-- the immediate subdirectory of the root directory, which is always one of
+-- "/home", "/Home", "/Users", "/[a-z]" or "/_*" (that's how the mount point
+-- is derived from the workspace path on host), none of which is to be mapped.
+-- Use home dir as a fallback for easier use.
+sbox_user_workspace = string.match(os.getenv("SAILFISH_SDK_SRC1_MOUNT_POINT") or sbox_user_home_dir,
+   "^/[^/]+")
+
 -- http://stackoverflow.com/a/4991602/337649
 function user_file_readable(name)
    local f=io.open(name,"r")